


Irresistible

by CherryPie0



Series: Kinktober 2019 [8]
Category: Iron Man (Movies), Marvel Cinematic Universe, Spider-Man (Tom Holland Movies)
Genre: Alpha Tony Stark, Alpha/Beta/Omega Dynamics, Alternate Universe, Anal Sex, Knotting, M/M, Mating Cycles/In Heat, Omega Peter Parker, Parent/Child Incest, Tony takes care of his boy, first heat
Language: English
Status: Completed
Published: 2019-10-08
Updated: 2019-10-08
Packaged: 2020-11-27 03:03:40
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,650
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20941223
Author URL: https://archiveofourown.org/users/CherryPie0/pseuds/CherryPie0
Summary: Day 7 - ScentIt's Peter's scent that gives him away, at last.Tony almost chokes as he breathes it in, recognizing the sweet, overpowering scent of an Omega in heat immediately.





	Irresistible

Tony should have known that something was wrong. Or maybe he did know but he simply didn't want to acknowledge it.

Peter and he have always been really close to one another, probably closer than most dads usually are with their sons, but since they have been all each other had for years now, no one thought much about it. It's simply their normal.

Lately, however, Peter has been even more clingy than usual.

He spends more time outside of his room and with Tony, mostly sitting next to him on the couch, pressing himself to his dad's body or curling up on his lap, nuzzling his chest. Tony doesn't question it. He likes having his little boy close to him, holding him in his arms where he knows he can protect him. He's still so small and innocent, the only moments Tony stops worrying about him it's when he has his son wrapped in his embrace.

He does find it kind of strange though, when Peter slips into his room one night, deciding to sleep there instead of his own bed. Peter seems sincere when he says that everything is fine when Tony asks him what's going on, so Tony doesn't pressure the matter any further. If his boy wants to sleep in his bed, then so be it.

But it doesn't stop there.

Sometimes, Peter finds him in his office and just comes to sit on his lap, staying there and letting him work, behaving like a good boy. He simply kisses Tony's cheek from time to time, nuzzling his beard, making pleased little hums: _is that your aftershave, daddy? smells so good. I like it_.

It's quite weird, but not unwelcome.

Tony notices other little things, too - like Peter's increased appetite and how he gets hot easier than usual, or the involuntary content sighs he lets out at every gentle touch Tony offers - but despite seeing everything, Tony's mind fails to put two and two together.

By the time he realizes what is going on, it's already too late.

It's Peter's scent that gives him away, at last.

Tony, being his father, finds Peter's scent familiar, comforting, so used to having him around that he barely even notices it.

That, until now.

Peter comes home from school with flushed red cheeks and hair sticking to his sweaty forehead, looking tense, his eyes darker than normal. Peter is on him in only a second, climbing into his lap, burying his face into the crook of Tony's neck, whimpering like he's in pain.

His scent hits Tony like a fucking truck. He almost chokes as he breathes it in, recognizing the sweet, overpowering scent of an Omega in heat immediately.

"I- I don't feel good, daddy," Peter whines and snuggles even closer to him - if that's even possible, that is -, burying himself into Tony's chest.

Tony is at loss of words for a few moments, suddenly unable to process this, not sure how he should proceed.

They weren't expecting Peter's first heat until months later; his boy is still only fifteen, after all. Most Omegas have their first heat after they've turned sixteen.

"P- Peter... Do you know what's happening, baby?" He asks gently, holding Peter close to his chest, stroking his back with a shaking hand.

"I, uh, I think so," Peter whispers in a small voice and Tony's heart clenches at how scared his son sounds.

"Hey, everything will be fine, okay? I'm here, I've got you. I'll help you through it, baby. Anything you need," Tony promises him and Peter pulls away to look at him, eyes glistening with unshed tears.

"You will?"

Tony chuckles and nods his head, leaning in to kiss Peter's forehead. "Of course I will, Pete. I always take care of you, don't I?"

Peter smiles and then resumes his position from before, pressing himself to Tony's chest again.

"I'm so glad you're here, daddy. Wh- when I kept hearing about Omegas having their first heat without an Alpha and how much they were suffering, I was so worried that this would happen to me, too. But you said you'll take care of me, right? You'll make this go away?"

The words bring dangerous thoughts to Tony's head and he gulps past the lump in his throat, trying his best to keep his voice steady as he answers.

"No, Peter, baby... This- this isn't how it works. But I promise I'll make it as less painf-"

"But- but you said you'll help me! And I just- I really need an Alpha, daddy - I can _feel_ it - and I don't trust anyone other than you. Oh... do you- do you not love me? Is that it?" Peter asks now, voice quivering, his brows furrowing and his bottom lip wobbling as he blinks a few tears back.

"Of course I love you, baby! I love you so, so, so much. You know that."

"Then why don't you want me? I need you so much, daddy. Please," Peter begs and Tony's words die in his throat when Peter grinds his hips against his, pressing their bodies firmly together.

He's terrified to realize that he's aroused, his cock fully hard in his pants right under his son's weight.

"Peter, don't-"

"Pl- please," Peter mewls and licks a long stripe across Tony's neck, making his cock give an involuntary twitch in response.

He takes a deep breath, trying to calm himself down, only to regret it right after when his senses get overwhelmed with Peter's intoxicating scent, sweet just like his little boy.

He inhales again before he can stop himself, tilting his head to nuzzle Peter's hair, dragging his nose lower, over Peter's ear, and he has almost reached his neck when his brain decides to function again.

He lifts Peter up and quickly gets up from the couch, ignoring Peter's cries of protest no matter how much it hurts to do so.

He paces across the room, desperately trying to figure out what he should do, his hard cock distracting him much more than Tony would like.

"It- it hurts, daddy, _please_," Peter whines, sounding like he's actually in a lot of pain, but Tony can't approach him as he is now. It's not safe. He turns his back to him and just breathes for a few moments, mustering all the self-control he has left.

This isn't supposed to happen. Fathers aren't supposed to be drawn to their sons' scent- they're not supposed to be _aroused_ by it, for fuck's sake. What the hell is wrong with him?

"D- daddy," Peter tries again in a desperate little voice and Tony turns back to him, can't ignore him anymore.

He doesn't expect to find Peter sitting on the couch with his legs spread wide while he's rubbing himself- no, not his cock, Tony realizes with a sharp exhale. Peter is rubbing his little hole through his sweats, a dark wet patch having formed on the grey fabric from Peter's slick.

Tony feels dizzy with arousal, everything inside him screaming to take and claim, to taste and kiss and bite, to mark and breed and make Peter _his_.

"Peter, you- you should go to your room," he says, rather impressed that he even managed to keep his voice steady and firm.

Peter moans in reply, looking too lost in his pleasure to actually listen to what Tony's saying, and then a loud cry of the word _daddy_ comes from Peter's parted mouth, a new wave of his scent assaulting Tony's senses, smelling even stronger than before.

Tony's eyes widen when his gaze lands on Peter's lap and he realizes that Peter has just come, creaming his pants just from barely even touching his hole.

It's too much- too fucking much, and Tony can't hold back any longer; he truly can't- and he doesn't fucking want to! He lets his instincts take over at last and can't help growling deep in his throat as he approaches his son that looks so beautifully ruined and smells like everything Tony ever wanted- and _more_.

Peter whimpers and immediately reaches for him, letting Tony pick him up, clinging to him as Tony carries him to his bedroom.

"D- daddy... Pl- please... I _need_, please..." Peter whines helplessly and tries to grind against Tony, almost sobbing when the friction proves to not be enough. Tony knows that even though Peter has just come, he felt no real relief; Omegas need to be filled- by toys if there's no other option, but preferably by an Alpha's cock and then by their knot.

If Tony's honest, he's glad he's the one to spend Peter's first heat with him; he couldn't trust anyone else to take care of his precious boy.

"Shhh, I'm here, sweetheart. Daddy will take care of you now," he reassures Peter, tries to offer as much comfort as he can until they reach the bed. Peter clutches at his shoulders and refuses to let him go when Tony tries to lower him on the mattress, managing to do so only when he orders Peter to be a good boy and behave.

Peter lies on the bed and looks at him with glistening, wide eyes, pleading Tony to give him what he needs. And Tony can't deny him anymore.

He tugs at Peter's sweatpants urgently, removing them with quick efficient movements, doing the same with Peter's t-shirt and then with his own clothes, as well, until they're both completely naked. He lets his eyes roam over Peter's small delicate body, indulging himself only for a few seconds, taking in how flushed Peter's milky skin is, how his cute little cock is already fully hard and leaking again, how his inner thighs are shining with his slick.

Then he's climbing into the bed, his patience already having worn thin, his cock throbbing, hanging heavy and hard between his legs, aching to slip into Peter's wet heat.

Peter's legs fall wide open instinctively the moment Tony is on the bed, and Tony settles between them, doesn't waste any time before bringing his fingers to Peter's entrance.

An incoherent sounds escapes Peter as Tony lets his fingertips brush over his son's rim, relishing how wet and ready he already is. He easily slides two fingers inside just to be sure that Peter can take him, not surprised to find his little body so eager, so welcoming; he was literally born to take an Alpha's cock, after all.

He withdraws his fingers soon after and can't resist bringing them to his mouth, grunting in pleasure when he tastes his boy's sweet slick. If Peter weren't suffering right now, Tony would take his time eating him out and he would stop only when Peter's sobbing, begging him to get his cock in him.

_Later_, Tony thinks to himself, fully aware that Peter's heat will last days; Tony will, of course, be there to tend to him through it all.

"Breathe for me, baby. Try to relax, okay? Daddy will make you feel good soon," he says gently and Peter nods, immediately doing what he was told to. Tony hums satisfied, caressing his thigh to help him; he's fucked Omegas in heat before - even in their first heat, on some occasions - and he has noticed they do better when you give them instructions, when you take the lead so they can relax and let themselves go completely and Peter doesn't seem to be any different, eager to follow Tony’s orders.

Tony hovers over him as he lines his cock up with Peter's entrance, welcoming Peter's moans the moment the head of his dick nudges against his rim.

"Shhh, daddy's here, baby. Everything will be alright," he says in a soothing voice, just like he used to do when Peter was younger and had nightmares, and Peter offers him a hopeful smile, his tense body slowly relaxing.

Tony smiles back and finally pushes forward, doesn't stop moving until his cock is fully buried inside Peter's body. He groans and resists moving right away, letting Peter get accustomed to the unfamiliar sensation first.

He pets Peter's damp hair, leaning in to kiss his sweaty forehead, and can't help smiling at the little whimpers his son lets out. He's so sweet, so good; Tony will never let him go. No one deserves his little boy; no one will ever be good enough for him.

"Can I move, darling?" He asks eventually and Peter nods his head, his hands gripping tightly Tony's shoulders.

Tony starts rocking his hips, being careful with his movements and keeping his eyes on Peter to make sure he's fine, getting encouraged when Peter seems to only feel pleasure, his legs wrapping around Tony's waist, urging him to go faster, to give him more.

"Yeah... That's it baby. You're doing so well," he says as he speeds up his pace, and Peter whines, his body arching beautifully into him, eagerly welcoming everything Tony offers him.

Despite the tightness of Peter's untouched body, his slick allows Tony's thick cock to slide in and out smoothly, Peter's slippery walls clinging to him as he moves. It feels as if the empty space inside his son's body was made just for him to fill, as if this has always been how it was supposed to happen.

"D- daddy... _Ah_\- oh God, daddy... feels so full," Peter whines and Tony's lips twitch up without his permission when he imagines how Peter will feel after Tony knots inside him, his dick twitching excitedly at the thought.

_Not yet_, he reminds himself; he has to make his little Omega feel good, first. Peter is still growing wetter and wetter as Tony fucks into him, still shaking and whimpering helplessly, his heat still at its worst. It's always hard during the first time, but Tony will do his best to stop his boy's suffering as soon as possible.

He snaps his hips at a steady, unforgiving pace, exactly what Peter seems to need right now, and leans closer to kiss and lick at the damp skin of his neck, Peter's sweat only making his scent more overwhelming. It's thrilling how even Peter's scent manages to drive him closer to the edge, how it awakes the Alpha instincts in him and all he wants to do is knot him and keep him like that, until everyone knows that Peter belongs to him.

"Harder, daddy... Alpha, _please_. I- I need it," Peter mewls in his sweet, _sweet_ voice, and Tony is happy to deliver, pounding into him with wild abandon, Peter's dripping hole making obscene, squelching sounds as Tony drives his cock deep inside him.

"How does it feel, baby?" Tony pants, mouthing up at Peter's neck and jaw. "Is daddy making you feel good?"

"S- so good, daddy. It doesn't hurt a- anymore," Peter says between his moans and Tony can't help smiling, warmth spreading through his body at the knowledge that he's helping his precious baby.

He starts when he feels lips pressed to his own and it takes him a few moments to realize that Peter is actually kissing him and that they had yet to kiss before this.

Peter is hesitant, brushing his lips over his gently, almost as if he's afraid.

_His sweet little boy!_ He probably hasn't kissed anyone before.

Tony takes charge of the kiss and Peter seems happy to just follow his lead, parting his lips willingly and letting Tony slide his tongue inside. It's wet and messy, and not that great for a first kiss, if Tony is to be honest, but the way he's pounding relentlessly into Peter doesn't allow much more. Still, Peter moans and melts into it, obviously enjoying it, his little body reacting beautifully to everything Tony does to him.

"Oh- oh God, _daddy_," Peter gasps against his mouth and Tony grins, knowing that he's found it. "Fuck, r- right there, daddy, _please_!!"

Tony only has to deliver one more thrust, hitting the magic little spot inside Peter with precision once more, and Peter comes just like that, his dick twitching between them, shooting his release on their stomachs while his little hole clenches tightly around Tony's hard cock. 

"That's it. Good boy," Tony praises as he keeps fucking him through his orgasm, and Peter whimpers weakly, his blunt nails digging into the muscles of Tony's shoulders, his body trembling as he tries to catch his breath.

"Daddy," he sighs, even now right after coming being greedy for more. He's so needy and insatiable; it's one of the things Tony adores about young Omegas. They can never get enough, always asking for more, demanding that their Alpha give them everything; and Tony always does. He's generous like that.

Besides, what kind of an Alpha would he be if he couldn't satisfy his Omega? Even more so, now, that said Omega is his lovely boy.

He fucks into him with hard forceful thrusts, feeling the base of his cock slowly starting to swell. Peter's slick walls loosen around him as Peter accepts his Alpha inside him just as he should.

"Do you want daddy's knot, sweetheart? Want me to fill and stretch your little hole?" He asks and Peter nods his head immediately, not hesitating before answering.

"Yes, please," he says breathlessly, looking both excited and terrified at the prospect of having his dad's knot inside him.

Tony knows that despite the fact that Peter's body is still so small and delicate, he's not fragile, he can handle this; his instincts are already preparing him to welcome an Alpha's knot inside him, after all.

"You're gonna have to turn around now, okay, baby? It'll be better this way," Tony tells him, knowing that they should be in a comfortable position, considering that they'll stay locked together long after he comes.

Peter obeys, as always eager to please, letting Tony manhandle him on his stomach, whining when Tony slides back in his wet, sloppy hole. Peter's thighs, Tony's balls, even the sheets underneath them are covered in Peter's slick, his opening absolutely soaking with his sweet, hot juices, probably wetter and more eager than any other Omega Tony has fucked before.

Tony lowers himself over him, his chest almost flush against his son's back, without, however, letting his weight crush Peter's smaller body, always careful to not cause him any discomfort. He begins moving immediately, his boy's rim catching around the subtle swell of his knot every time he thrusts in and out, eliciting broken little whines from Peter.

He brings his mouth to the crook of Peter's neck, not able to resist, and nibbles on the flesh gently, before biting harder at the tender skin, soothingly licking and kissing the same spot when he pulls away.

He covers Peter's flawless creamy skin with bite marks, tasting every inch of his sweet boy that he can reach, knowing that no one except him will see Peter during the next few days. There's, of course, no way that Tony is letting him go anywhere while he's on his first heat, which also means that no one will question the beautiful marks and bruises Tony leaves all over Peter's perfect body.

He can feel his knot fattening up faster now and he slows down, sensing the difficulty of Peter's body to take him inside, his rim stretching impossibly wide to accommodate him. He pumps his cock in and out carefully, growling deep in his throat at the tantalizing but absolutely delicious slow drag of his cock in and out of Peter's weeping hole.

Peter is sobbing softly into the pillow, his body right now being both sensitive and greedy, needing more but not able to wait any longer for his Alpha's seed. Luckily, it takes Tony only a few more moments to reach his climax, and he thrusts all the way in, his knot completely swallowed in Peter's body.

He grunts as he starts spilling inside him, spurts after spurts of thick cum flooding Peter's hole, his knot making sure that every single drop of it stays inside, keeping his baby perfectly stuffed with cum and cock.

He suddenly feels Peter tense and shake again as another orgasm hits him, fat tears rolling down his cheeks by the time Tony has stopped coming, his knot now finally fully engorged.

"Fuck," Tony groans - he usually doesn't curse in front of Peter but he guesses it doesn't really matter now - and leans closer to kiss Peter's wet cheek, smiling at the way his son turns his head to accept the kisses.

Then Tony moves them around so they're both lying on their sides with him spooning Peter from behind, his movements careful and gentle, aware of how tender Peter's thoroughly fucked, full hole is.

"How are you, sweetheart?" He asks and nuzzles Peter's hair and neck, loving how he can smell their mixed scents on Peter's skin. He snakes an arm around his little waist, his hand finding the small bump on Peter's stomach, reveling in how it feels round and bloated, probably both because of the seed and the cock still inside him.

"I think I'm fine. This- this actually feels really nice. Thank you, daddy," he says, almost shyly, and Tony smiles, his heart swelling with affection, and places a kiss on the back of Peter's head. "Will this last long?"

"No, not too long. Is it uncomfortable?" Tony asks, hoping that it's at least not painful for Peter.

"No no, it's fine. I don't mind. Just- I feel really tired and I kinda wanna sleep," Peter mumbles sheepishly, failing to fight back a yawn.

_Aw, he's still his adorable, little baby!_

"You can sleep, baby, it's okay. Daddy will be here when you wake up," Tony reassures him and Peter hums happily, eyes fluttering close.

His boy will definitely need some rest, Tony thinks, sure that Peter will be up sooner than later, already asking for more.

**Author's Note:**

> Thank you for reading!!!❤️ Kudos and comments make my day 😁💞


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